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Broszio, Kai; Zauner, Johannes

FG Lichttechnik

This data set holds 3D construction and printing files for apertures for spectroradiometers (JETI specbos 1201 und specbos 1211) to mimic the human binocular field of view in the context of non-image-forming effects of light. The PDF document holds an overview of the adapters and apertures and explains which 3D construction and printing files belongs to the specific part. The zip-file 'adapter.zip' holds all these files for the adapters and cuffs and the zip-file 'FOV_aperture.zip' holds all these files for the apertures. Background: In many studies, the vertical illuminance or the vertical irradiance in the corneal plane is traditionally used to determine non-visual light effects of an illumination situation in order to describe the light entering the eye. For this purpose, the illuminance is measured with a diffuser in the so-called 2π geometry. Due to anatomical conditions, the human visual field does not correspond to that of a half-space, but is restricted upward and downward. The relevant standard for melanopic light effects, CIE S026, explicitly points this out. However, it is not yet clear which deviations are to be expected due to the visual field limitation. In order to estimate the influence, measurements were carried out in different lighting situations in the laboratory (light from different directions) and under practical conditions (light typically from above). For this purpose, 3D-printed visual field apertures were used in accordance with CIE S026 as an attachment to spectral measurement technology in eye position. Particularly in real lighting situations where the lighting is installed overhead, the measured values with the visual field aperture can deviate significantly from the vertical illumination intensity without aperture. These measurements show a reduction in the values due to the field of view aperture of up to 60 %. Typically, there is a comparable reduction for the measured illuminance and the MEDI value, i.e. spectral deviations were almost exclusively uncritical in the situations investigated. This generalization is valid because the distribution of light in the field of view is usually spectrally uniform. In contrast, with large chromatic variations, the visual field aperture leads to strong spectral changes in addition to a reduction in the general irradiance level. In an artificial laboratory situation, for example, the melanopic action factor changed by more than a factor of 2 for the same illumination only due to the aperture.